1. Field of the Invention
The present general inventive concept relates to a thermal transfer type image forming apparatus using an ink ribbon, and a method of detecting a remaining amount of the ink ribbon.
2. Description of the Related Art
An ink ribbon is a source for supplying transfer ink used for a thermal transfer type image forming apparatus, which includes a sublimation type or a fusing type image forming apparatus. The ink ribbon is typically loaded in a cassette installed in the image forming apparatus. The ink ribbon has a plurality of print areas corresponding to the size of a print paper, and each of the print areas is coated with an ink layer. The ink ribbon is wound around a supply reel and a take-up reel to be loaded in the cassette.
There are a variety of types of ink ribbons, according to the sizes of the print paper, such as an A6 size or a card size, the sensitivity of a dye (or a pigment), or the presence of an over coating area. A user selects an appropriate ink ribbon cassette according to the purpose of printing and installs the selected ink ribbon cassette in the image forming apparatus. Accordingly, there may be a case in which the ink ribbon cassette needs to be replaced with another type before it is totally consumed.
When the ink ribbon cassette is replaced with a new ink ribbon cassette, the printer needs to change a system control method or a print condition according to the type of the new ink ribbon cassette. Thus, an identification mark, such as an identification hole or an optical mark, is provided in the case of the ink ribbon cassette. The identification mark is detected using a sensor so that the total number of printable pages or the type of ink ribbon can be determined. Since this information is intrinsic to the ink ribbon, the information remains unchanged regardless of increments of the number of printed pages. Thus, although different types of ink ribbon cassettes can be interchanged, the printer can easily detect the type of ink ribbon.
However, since the ink ribbon is wound around the supply reel and the take-up reel, if the number of printed pages is not recorded, it is difficult to recognize how many more pages the printer can print using the ink ribbon. In the case in which the same ink ribbon is used until no ink remains, it is possible to recognize the number of pages which can printed in the future (i.e. the remaining amount of the ink ribbon) by resetting the number of printable pages whenever the ink ribbon cassette is replaced and recording the accumulated number of printed pages in a memory. In most cases, however, when the purpose of printing changes, for example, an image is to be printed on A5-sized paper after printing on A6-sized paper, the ink ribbon cassette is generally replaced corresponding to the purpose of printing. Therefore, although the number of printed pages is recorded in the memory, the remaining amount of the ink ribbon is difficult to determine.